On an evolved packet system (EPS) network, user equipment (UE) accesses an evolved packet core (EPC) through a serving gateway (SGW) on a radio access network, and accesses an external packet data network (PDN) through a PDN GW. A policy control entity may dynamically generate a service data policy rule according to service information about the UE, and communicate the service data policy rule to the PDN GW and the SGW, thus implementing service-level dynamic policy control on the data.
In the prior art, the process of establishing a data connection to access a PDN by the UE includes: the SGW forwards a connection setup message sent from the UE to a PDN GW that corresponds to the PDN; the PDN GW returns a connection setup ACK to the SGW; the SGW returns a response indicating the completion of data connection setup to the UE.
The SGW may be a network element (NE) where a control plane and a user plane are separated or integrated. For example, the SGW may be a mobility management entity (MME) or a GW on the EPS network, or an integrated serving GPRS support node (SGSN) on a third generation (3G) network.
During the implementation of the present application, the inventor discovers the following problems in the prior art: When the UE accesses the core network for the first time, the UE may not request the allocation of an Internet Protocol (IP) address but requests only the setup of a data channel. If the network needs to implement policy control, the prior policy control procedures related to the EPS network data connection are not applicable to scenarios where no IP connection is established for the data channel between the UE and the PDN GW. This is because the prior policy control session is connected over IP. In addition, for the mobility management protocol between GWs, the prior art is applicable to only the GPRS Tunneling Protocol (GTP) not requiring an IP address and is inapplicable to the mobile IP protocol.